Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Triangulum Pinwheel: 01-28 (99), 01-29 (97), 01-30 (96), 01-31 (93), 02-01 (91) — by astronomy; check the weather when the night is within four days.

2038-01-28astronomy score per night — click a bar for that night2038-02-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-01-28 Thu	99	—	unknown	19:10–22:55 (good, 3.75 h)	79.2° 17:25	10.88	39%	149.7°
2038-01-29 Fri	97	—	unknown	19:10–22:55 (good, 3.75 h)	79.2° 17:20	10.85	28%	140.4°
2038-01-30 Sat	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:15	10.82	19%	129.4°
2038-01-31 Sun	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.2° 17:15	10.79	11%	117.8°
2038-02-01 Mon	91	—	unknown	19:15–22:40 (good, 3.42 h)	79.2° 17:10	10.75	6%	106.1°
2038-02-02 Tue	88	—	unknown	19:15–22:40 (good, 3.42 h)	79.2° 17:05	10.72	2%	94.3°
2038-02-03 Wed	87	—	unknown	19:15–22:35 (good, 3.33 h)	79.2° 17:00	10.69	0%	82.7°
2038-02-04 Thu	84	—	unknown	19:20–22:30 (good, 3.17 h)	79.1° 17:00	10.65	0%	71.4°
2038-02-05 Fri	82	—	unknown	19:20–22:25 (good, 3.08 h)	79.2° 16:55	10.62	3%	60.4°
2038-02-06 Sat	77	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:50	10.58	7%	49.9°
2038-02-07 Sun	70	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:45	10.55	13%	40.2°
2038-02-08 Mon	62	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:40	10.51	20%	31.9°
2038-02-09 Tue	50	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:40	10.47	28%	26.0°
2038-02-10 Wed	41	—	unknown	19:25–21:45 (good, 2.33 h)	79.2° 16:35	10.44	36%	24.5°
2038-02-11 Thu	31	—	unknown	19:25–20:40 (good, 1.25 h)	79.2° 16:30	10.4	46%	28.1°
2038-02-12 Fri	24	—	unknown	19:25–22:20 (marginal, 2.92 h)	79.2° 16:25	10.36	55%	35.4°
2038-02-13 Sat	20	—	unknown	19:30–22:10 (marginal, 2.67 h)	79.2° 16:20	10.32	65%	44.8°
2038-02-14 Sun	19	—	unknown	19:30–22:00 (marginal, 2.5 h)	79.2° 16:20	10.28	74%	55.5°
2038-02-15 Mon	19	—	unknown	19:30–21:55 (marginal, 2.42 h)	79.2° 16:15	10.24	83%	67.1°
2038-02-16 Tue	22	—	unknown	19:30–22:00 (marginal, 2.5 h)	79.2° 16:10	10.2	90%	79.3°
2038-02-17 Wed	27	—	unknown	19:30–20:20 (good, 0.83 h)	79.2° 16:05	10.16	96%	92.1°
2038-02-18 Thu	32	—	unknown	19:35–21:10 (good, 1.58 h)	79.1° 16:00	10.12	99%	105.2°
2038-02-19 Fri	38	—	unknown	19:35–21:20 (good, 1.75 h)	79.2° 16:00	10.08	100%	118.4°
2038-02-20 Sat	39	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:55	10.04	98%	131.2°
2038-02-21 Sun	43	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:50	10.0	92%	143.0°
2038-02-22 Mon	42	—	unknown	19:40–21:20 (good, 1.67 h)	79.2° 15:45	9.95	85%	152.2°
2038-02-23 Tue	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:45	9.91	76%	155.6°
2038-02-24 Wed	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:40	9.87	65%	151.6°
2038-02-25 Thu	37	—	unknown	19:40–21:05 (good, 1.42 h)	79.2° 15:35	9.82	54%	142.8°
2038-02-26 Fri	34	—	unknown	19:45–21:05 (good, 1.33 h)	79.2° 15:30	9.78	43%	132.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-01-28&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.